The hydrazide-hydrazone 3 reacted with benzenediazonium chloride to give the phenylhydrazone derivative 5. The latter underwent a series of hetero-cyclization reactions to give pyridazine, 1,2,3-triazole and pyrazole derivatives. The antitumor evaluation of the newly synthesized products against the three cancer cells lines namely breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF-268) showed that some of them have higher inhibitory effects towards the three cell lines compared to the standard.